Motor Road Transport For Commercial Purposes
(Liquid Fuel, Steam, Electricity)

154 MOTOR ROAD TRANSPORT Vans may often be seen running with. their wheels out of line. This may have occurred as the result of a slight accident : from striking the kerb sharply either from a side-slip or from careless driving ; from a weak axle ; or again, from strained or worn steering connections. The tyres of a van running with the wheels out of alignment are subjected to a continuous and severe scraping action. This fault is easy to detect, either by lining up the wheels with a string or a piece of wood, or by examining the surface of the tyres. The defect should be remedied at once, for excessive and entirely unnecessary wear will take place so long as the wheels do not run truly. Lastly, if overloading and excessive speed are permitted, the life of the tyres will, without the shadow of a doubt, be short. Lubricants. It may seem absurd to think of lubricating oil as being a definite component part in the construction of a motor chassis, nevertheless, it is so in practice. Without an insulating film of lubricant between two bearing surfaces, it is not possible to have con- tinuous relative motion for any length of time, nor even occasional movement, without wear. This film, therefore, in effect becomes a constructional member. It can be readily seen that the life of a bearing depends almost entirely upon the qjaality of the lubri- cating substan.ce, and upon its presence where and when it is most wanted. There is probably no machinery in the world which is subjected to such neglect in this matter as the motor car. Any liquid, so long as it resembles oil—and very often the refiners are to blame for the deficiency—is poured into a motor engine, quite irrespective of whether the grade is suitable to the piston speed, the working temperature